大倾角近距离煤层开采矿压显现规律研究

Research on the Manifestation Law of Mining Pressure in High Angle and Close Range Coal Seam Mining

为实现大倾角近距离煤层高效、安全开采,利用数值模拟结合工程实践对工作面顶板岩层矿压显现进行研究。对不同工作面推进距离下的垂直应力进行分析,发现大倾角近距离下煤层开采时,由于上煤层开采使其底板应力释放,出现下煤层工作面中、下部应力较小,应力集中系数减小,顶板上部应力较大的现象。对不同开采方案下的应力进行对比,发现大倾角近距离煤层下部煤层开采受上煤层开采的扰动,具有明显的卸压扰动现象。同时通过对不同区域下的工作面支架阻力进行分析,中部区域来压超前于上部和下部区域5~15 m,工作来压呈现为“先中再上后下”的特征,为大倾角近距离煤层开采提供参考。

In order to achieve efficient and safe mining of coal seams with high dip angles and close distances,numerical simulation combined with engineering practice was used to study the mining pressure manifestation of the roof rock layer in the working face.Firstly,the vertical stress under different working face advancement distances was analyzed.It was found that during the mining of coal seams with high dip angles and close distances,the stress on the bottom plate was released due to the mining of the upper coal seam,resulting in a smaller stress in the middle and lower parts of the lower coal seam,a reduced stress concentration coefficient,and a larger stress value in the upper part of the roof.By comparing the stress under different mining schemes,it was found that the lower coal seam of the steep and close range coal seam was disturbed by the upper coal seam mining,and there was a significant phenomenon of pressure relief disturbance.At the same time,by analyzing the resistance of the working face support in different areas,it was found that the pressure in the central area was 5~15 meters ahead of the upper and lower areas,and the working pressure showed a characteristic of"first in the middle,then up and then down",providing reference for the mining of large angle and close distance coal seams.